Peter: The first thing I'd suspect is lightning or a surge from nearby lightning coming down the antenna spigot. Having spent much of my career around radio equipment, I've seen many charred boards caused by lightning. The path taken within the board does not follow any obvious logical path. Lightning is like the proverbial 800 pound gorilla - it goes where it wants to go.
Was the antenna installed according to the National Electric Code ? Cheers, Jack Jacob Z. Schanker, P.E. Director of Agency Compliance Microwave Data Systems 175 Science Parkway Rochester, NY 14620 USA +716 242 8454 (voice) +716 241 5590 (fax) jschan...@mdsroc.com ------------------------------------------ > ---------- > From: pe...@itl.co.il[SMTP:pe...@itl.co.il] > Sent: Thursday, November 05, 1998 5:16 PM > To: emc-p...@ieee.org > Subject: Burning Card Module > > Dear Members, > > I am sure some of you can give me ideas on how to analyze a card > module which in four different occassions caused charring and > smoke within the equipment. In all cases, fire did not spread and > the charring occurred in all cases, arounf decoupling SMT > capacitors located between the Vcc and ground. > > The subject card sits in an industrial type computer within a GSM > equipment. The card is fed by 5 V and 12 Vdc from the computer > power supply and employs two SE:V interfaces. It employs a > piggy board with a receiver with direct connection to an external > outddor antenna. > > Any suggestions how this may have happened in the field, on four > different occassions and the charring/burning occured around the > decouplng capacitors. > > For this let us assume PWB is flame rated 94V-0 and is > Recognized. > > Regards, > PETER S. MERGUERIAN > MANAGING DIRECTOR > PRODUCT TESTING DIVISION > I.T.L. (PRODUCT TESTING) LTD. > HACHAROSHET 26, P.O.B. 211 > OR YEHUDA 60251, ISRAEL > > TEL: 972-3-5339022 > FAX: 972-3-5339019 > E-MAIL: pe...@itl.co.il > Visit our Website: http://www.itl.co.il > > --------- > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to majord...@ieee.org > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to ed.pr...@cubic.com, > j...@gwmail.monarch.com, ri...@sdd.hp.com, or > roger.volgst...@compaq.com (the list administrators). > --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.org with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, j...@gwmail.monarch.com, ri...@sdd.hp.com, or roger.volgst...@compaq.com (the list administrators).
